Dihydropyrimidinyl benzazepine carboxamide compounds

ABSTRACT

This invention relates to new benzazepine carboxamide compounds of the formulawherein X and R1 to R6 are as defined in the description and in the claims, as well as pharmaceutically acceptable salts thereof. These compounds are TLR8 agonists and may therefore be useful as medicaments for the treatment of diseases such as cancer, autoimmune diseases, inflammation, sepsis, allergy, asthma, graft rejection, graft-versus-host disease, immunodeficiencies, and infectious diseases.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. application Ser. No.16/213,308, filed Dec. 7, 2018, which is a Continuation of InternationalApplication No. PCT/EP2017/064107, filed Jun. 9, 2017, claiming priorityto International Application No. PCT/CN2016/085471, filed Jun. 12, 2016,which applications are incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to novel dihydropyrimidinyl benzazepinecarboxamide compounds having pharmaceutical activity, their manufacture,pharmaceutical compositions containing them and their potential use asmedicaments.

In particular, the present invention relates to compounds of the formula

wherein X and R¹ to R⁶ are as described below, or to pharmaceuticallyacceptable salts thereof.

The compounds are TLR agonists. More particularly, the compounds areTLR8 agonists and may be useful for the treatment and prevention (e.g.vaccination) of cancer, autoimmune diseases, inflammation, sepsis,allergy, asthma, graft rejection, graft-versus-host disease,immunodeficiencies, and infectious diseases.

Toll-like receptors (TLRs) are a family of membrane-spanning receptorsthat are expressed on cells of the immune system like dendritic cells,macrophages, monocytes, T cells, B cells, NK cells and mast cells butalso on a variety of non-immune cells such as endothelial cells,epithelial cells and even tumor cells (Kawai et al., Immunity, 2011, 34,637-650, Kawai et al., Nat. Immunol., 2010, 11, 373-384). TLRs thatrecognize bacterial and fungal components are expressed on the cellsurface (i.e. TLR1, 2, 4, 5 and 6), while others that recognize viral ormicrobial nucleic acids like TLR3, 7, 8 and 9 are localized to theendolysosomal/phagosomal compartment (Henessy et al. Nat. Rev. DrugDiscovery 2010, 9, 293-307) and predominantly found to be expressed bycells of the myeloid lineage. TLR ligation leads to activation of NF-κBand IRF-dependent pathways with the specific activation sequence andresponse with respect to the specific TLR and cell type. While TLR7 ismainly expressed in all dendritic cells subtypes (DC and here highly inpDC, plasmacytoid DC) and can be induced in B cells upon IFNαstimulation (Bekeredjian-Ding et al. J. Immunology 2005, 174:4043-4050),TLR8 expression is rather restricted to monocytes, macrophages andmyeloid DC. TLR8 signaling via MyD88 can be activated by bacterialsingle stranded RNA, small molecule agonists and lately discoveredmicroRNAs (Chen et al. RNA 2013, 19:737-739). The activation of TLR8results in the production of various pro-inflammatory cytokines such asIL-6, IL-12 and TNF-α as well as enhanced expression of co-stimulatorymolecules, such as CD80, CD86, and chemokine receptors (Cros et al.Immunity 2010, 33:375-386). In addition, TLR8 activation can induce typeI interferon (IFNβ) in primary human monocytes (Pang et al. BMCImmunology 2011, 12:55).

Small molecule agonists for both the TLR7 and TLR8 receptor as well asanalogs modified for use as vaccine adjuvants or conjugates have beenidentified in many patents (i.e. WO1992015582, WO2007024612,WO2009111337, WO2010093436, WO2011017611, WO2011068233, WO2011139348,WO2012066336, WO2012167081, WO2013033345, WO2013166110, andUS2013202629). Clinical experience has been obtained mainly for TLR7agonists, but only very few clinical studies focused on using highlyspecific TLR8 agonists. To date, the only FDA (U.S. Food and DrugAdministration)-approved small molecule drug is the TLR7 agonistimiquimod (ALDARA™) as a topical agent for the treatment of genitalwarts, superficial basal cell carcinoma and actinic keratosis. Systemicapplication however of the early TLR7 agonists like resiquimod has beenabandoned due to intolerable cardiotoxicity observed upon globalchemokine stimulation at therapeutic levels (Holldack, Drug DiscoveryToday, 2013, 1-4). Knowledge about TLR8 agonists is less advanced andmostly restricted to data with early mixed TLR7/8 agonists likeresiquimod. For the resiquimod agonist, however, the stimulatorycapacity of the TLR7 is superior compared to the activation of the TLR8,so that most of the effects of resiquimod are dominated by the effect ofTLR7 activity. More recently, TLR8 specific compounds like VTX-2337 havebeen described by VentiRX Pharmaceuticals (i.e. WO 2007024612), allowingfor the first time to analyse the specific role of TLR8 withoutactivation of TLR7 at the same time. At present there is still a needfor small molecule TLR8 agonists, specifically those with improvedpotency or selectivity.

The present invention is directed to benzazepine compounds with improvedcellular potency over known TLR8 agonists of this type for use in thetreatment of cancer, preferably solid tumors and lymphomas, and forother uses including the treatment of certain skin conditions ordiseases, such as atopic dermatitis, the treatment of infectiousdiseases, preferably viral diseases, and for use as adjuvants invaccines formulated for use in cancer therapy or by desensitizing of thereceptors by continuous stimulation in the treatment of autoimmunediseases.

The new compounds are characterized by improved cellular potency at TLR8compared to known TLR8 agonists such as VTX-2337. In addition, thesecompounds are highly specific towards TLR8 and possess only low or evenno activity towards TLR7. Due to the more restricted expression patternof TLR8 less severe side effects when administered systemically areexpected and thus the compounds possess advantageous properties comparedto combined TLR7/8 agonists.

SUMMARY OF THE INVENTION

The present invention relates to benzazepine-4-carboxamide compounds ofthe formula

wherein

-   R¹ is C₃₋₇-alkyl;-   R² is C₃₋₇-alkyl or C₃₋₇-cycloalkyl-C₁₋₇-alkyl;-   R³ is hydrogen or C₁₋₇-alkyl;-   R⁴ is hydrogen or C₁₋₇-alkyl;-   R⁵ is selected from the group consisting of hydrogen, halogen,    C₁₋₇-alkyl and C₁₋₇-alkoxy;-   R⁶ is selected from the group consisting of hydrogen, halogen,    C₁₋₇-alkyl and C₁₋₇-alkoxy;-   X is N or CR⁷, wherein R⁷ is selected from the group consisting of    hydrogen, halogen, C₁₋₇-alkyl and C₁₋₇-alkoxy;    or pharmaceutically acceptable salts thereof.

The invention is also concerned with processes for the manufacture ofcompounds of formula I.

The invention also relates to pharmaceutical compositions comprising acompound of formula I as described above and a pharmaceuticallyacceptable carrier and/or adjuvant.

A further aspect of the invention is the use of compounds of formula Ias therapeutic active substances for the treatment of diseases that canbe mediated with TLR agonists, in particular TLR8 agonists. Theinvention thus also relates to a method for the treatment of a diseasethat can be mediated with TLR agonists such as for example cancer andautoimmune or infectious diseases.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Furthermore, the followingdefinitions are set forth to illustrate and define the meaning and scopeof the various terms used to describe the invention.

The nomenclature used in this application is based on IUPAC systematicnomenclature, unless indicated otherwise.

The term “compound(s) of this invention” and “compound(s) of the presentinvention” refers to compounds of formula I and solvates or saltsthereof (e.g., pharmaceutically acceptable salts).

The term “substituent” denotes an atom or a group of atoms replacing ahydrogen atom on the parent molecule.

The term “lower alkyl” or “C₁₋₇-alkyl”, alone or in combination,signifies a straight-chain or branched-chain optionally substitutedalkyl group with 1 to 7 carbon atoms, in particular a straight orbranched-chain alkyl group with 1 to 6 carbon atoms and moreparticularly a straight or branched-chain alkyl group with 1 to 4 carbonatoms. Examples of straight-chain and branched C₁₋₇-alkyl groups aremethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, theisomeric pentyls, the isomeric hexyls and the isomeric heptyls. Methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl areparticularly preferred.

The term “C₃₋₇-alkyl” likewise refers to a straight-chain orbranched-chain alkyl group with 3 to 7 carbon atoms as defined above.n-propyl is particularly preferred.

The term “C₃₋₇-cycloalkyl-C₁₋₇-alkyl” refers to lower alkyl groups asdefined above wherein at least one of the hydrogen atoms of the loweralkyl group is replaced by a cycloalkyl group. Among the cycloalkylalkylgroups of particular interest is cyclopropylmethyl.

The term “cycloalkyl” or “C₃₋₇-cycloalkyl” denotes a saturatedcarbocyclic group containing from 3 to 7 carbon atoms, such ascyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl, moreparticularly cyclopropyl.

The term “C₃₋₇-cycloalkyl-C₁₋₇-alkyl” refers to lower alkyl groups asdefined above wherein at least one of the hydrogen atoms of the loweralkyl group is replaced by a cycloalkyl group. Among the lowercycloalkylalkyl groups of particular interest is cyclopropylmethyl.

The term “halogen” refers to fluoro, chloro, bromo and iodo, withfluoro, chloro and bromo being of particular interest. Moreparticularly, halogen refers to fluoro or chloro.

The term “lower alkoxy” or “C₁₋₇-alkoxy” refers to the group R′—O—,wherein R′ is lower alkyl and the term “lower alkyl” has the previouslygiven significance. Examples of lower alkoxy groups are methoxy, ethoxy,n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec.-butoxy and tert-butoxy,in particular methoxy.

The term “pharmaceutically acceptable” denotes an attribute of amaterial which is useful in preparing a pharmaceutical composition thatis generally safe, non-toxic, and neither biologically nor otherwiseundesirable and is acceptable for veterinary as well as humanpharmaceutical use.

Compounds of formula I can form pharmaceutically acceptable salts. Theterm “pharmaceutically acceptable salts” refers to those salts whichretain the biological effectiveness and properties of the free bases orfree acids, which are not biologically or otherwise undesirable.Pharmaceutically acceptable salts include both acid and base additionsalts. The salts are for example acid addition salts of compounds offormula I with physiologically compatible mineral acids, such ashydrochloric acid, hydrobromic acid, nitric acid, carbonic acid,sulfuric acid, sulfurous acid or phosphoric acid; or with organic acids,such as methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonicacid, formic acid, acetic acid, propionic acid, glycolic acid, pyruvicacid, oxylic acid, lactic acid, trifluoroacetic acid, citric acid,fumaric acid, maleic acid, malonic acid, tartaric acid, benzoic acid,cinnamic acid, mandelic acid, embonic acid, succinic acid or salicylicacid. In addition, pharmaceutically acceptable salts may be preparedfrom addition of an inorganic base or an organic base to the free acid.Salts derived from an inorganic base include, but are not limited to,the sodium, potassium, lithium, ammonium, calcium, magnesium, zinc,copper, manganese and aluminium salts and the like. Salts derived fromorganic bases include, but are not limited to salts of primary,secondary, and tertiary amines, substituted amines including naturallyoccurring substituted amines, cyclic amines and basic ion exchangeresins, such as isopropylamine, trimethylamine, diethylamine,triethylamine, tripropylamine, ethanolamine, lysine, arginine,histidine, caffeine, procaine, hydrabamine, choline, betaine,ethylendiamine, glucosamine, methylglucamine, theobromine, piperazine,N-ethylpiperidine, piperidine and polyamine resins. The compound offormula I can also be present in the form of zwitterions.Pharmaceutically acceptable salts of compounds of formula I ofparticular interest are the sodium salts or salts with tertiary amines.

The compounds of formula I can also be solvated, e.g., hydrated. Thesolvation can be effected in the course of the manufacturing process orcan take place e.g. as a consequence of hygroscopic properties of aninitially anhydrous compound of formula I (hydration). The term“pharmaceutically acceptable salts” also includes physiologicallyacceptable solvates.

The term “agonist” denotes a compound that enhances the activity ofanother compound or receptor site as defined e.g. in Goodman andGilman's “The Pharmacological Basis of Therapeutics, 7th ed.” in page35, Macmillan Publ. Company, Canada, 1985. A “full agonist” effects afull response whereas a “partial agonist” effects less than fullactivation even when occupying the total receptor population. An“inverse agonist” produces an effect opposite to that of an agonist, yetbinds to the same receptor binding-site.

The term “half maximal effective concentration” (EC₅₀) denotes theplasma concentration of a particular compound required for obtaining 50%of the maximum of a particular effect in vivo.

The term “therapeutically effective amount” denotes an amount of acompound of the present invention that, when administered to a subject,(i) treats or prevents the particular disease, condition or disorder,(ii) attenuates, ameliorates or eliminates one or more symptoms of theparticular disease, condition, or disorder, or (iii) prevents or delaysthe onset of one or more symptoms of the particular disease, conditionor disorder described herein. The therapeutically effective amount willvary depending on the compound, disease state being treated, theseverity or the disease treated, the age and relative health of thesubject, the route and form of administration, the judgment of theattending medical or veterinary practitioner, and other factors.

In detail, the present invention relates to compounds of the formula

wherein

-   R¹ is C₃₋₇-alkyl;-   R² is C₃₋₇-alkyl or C₃₋₇-cycloalkyl-C₁₋₇-alkyl;-   R³ is hydrogen or C₁₋₇-alkyl;-   R⁴ is hydrogen or C₁₋₇-alkyl;-   R⁵ is selected from the group consisting of hydrogen, halogen,    C₁₋₇-alkyl and C₁₋₇-alkoxy;-   R⁶ is selected from the group consisting of hydrogen, halogen,    C₁₋₇-alkyl and C₁₋₇-alkoxy;-   X is N or CR⁷, wherein R⁷ is selected from the group consisting of    hydrogen, halogen, C₁₋₇-alkyl and C₁₋₇-alkoxy;    or pharmaceutically acceptable salts thereof.

In a particular aspect, the invention relates to compounds of formula I,wherein R¹ is n-propyl.

In another aspect, provided are compounds of formula I, wherein R² isselected from the group consisting of n-propyl, isobutyl andcyclopropylmethyl. In particular, the invention is concerned withcompounds of formula I, wherein R¹ and R² are n-propyl.

In a further aspect, the invention relates to compounds of formula I asdefined herein before, wherein R³ is hydrogen or C₁₋₇-alkyl, inparticular hydrogen or methyl. In another aspect, the invention relatesto compounds of formula I as defined herein before, wherein R⁴ ishydrogen or C₁₋₇-alkyl, in particular hydrogen or methyl. Moreparticularly, both R³ and R⁴ are hydrogen. In another particular aspect,both R³ and R⁴ are methyl.

In a further aspect, provided are compounds of formula I, wherein X isCR⁷ and R⁷ is selected from the group consisting of hydrogen, halogen,C₁₋₇-alkyl and C₁₋₇-alkoxy. More particularly, R⁷ is hydrogen orhalogen. In particular, halogen is chloro.

In another aspect, provided are compounds of formula I, wherein X is N.

In a further aspect, the invention relates to compounds of formula I,wherein R⁵ is selected from the group consisting of hydrogen, halogenand C₁₋₇-alkyl. More particularly, R⁵ is hydrogen, chloro, fluoro ormethyl.

In another aspect, provided are compounds of formula I, wherein R⁶ isselected from the group consisting of hydrogen, halogen and C₁₋₇-alkoxy.In particular, R⁶ is hydrogen, chloro or methoxy.

Particular compounds of the invention are the following:

-   2-amino-8-(1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(1,4-dihydropyrido[3,4-d]pyrimidin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-N-(cyclopropylmethyl)-8-(1,4-dihydroquinazolin-2-yl)-N-propyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(1,4-dihydroquinazolin-2-yl)-N-isobutyl-N-propyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(5-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(7-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(4,4-dimethyl-1H-quinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(6-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(5-methyl-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,-   2-amino-8-(5-fluoro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,    and-   2-amino-8-(6-methoxy-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide.

A further aspect of the present invention is the process for themanufacture of compounds of formula I as defined above, which processcomprises

a) coupling a compound of the formula II

wherein R¹ and R² are as defined in claim 1 and PG is a protectinggroup, with a compound of the formula III

wherein X and R³, R⁴, R⁵ and R⁶ are as defined in claim 1 and PG₁ is aprotecting group, under basic conditions in the presence of a couplingagent and removing the protecting groups PG and PG₁ under acidicconditions to obtain a compound of the formula I

wherein X and R¹ to R⁶ are as defined in claim 1, and, if desired,converting the compound obtained into a pharmaceutically acceptablesalt.

It will be appreciated, that the compounds of general formula I in thisinvention may be derivatised at functional groups to provide derivativeswhich are capable of conversion back to the parent compound in vivo.Physiologically acceptable and metabolically labile derivatives, whichare capable of producing the parent compounds of general formula I invivo are also within the scope of this invention.

In particular, a suitable protecting group PG is an amino-protectinggroup selected from Boc (tert-butoxycarbonyl), benzyl (Bz) andbenzyloxycarbonyl (Cbz). In particular, the protecting group is Boc.

“Removing the protecting group PG under acidic conditions” meanstreating the protected compound with acids in a suitable solvent, forinstance trifluoroacetic acid (TFA) in a solvent such as dichloromethane(DCM) can be employed.

A suitable “coupling agent” for the reaction of compounds of formula IIwith amines of formula III is selected from the group consisting ofN,N′-carbonyldiimidazole (CDI), N,N′-dicyclohexylcarbodiimide (DCC),1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI),1-[bis(dimethylamino)-methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium-3-oxidehexafluorophosphate (HATU), 1-hydroxy-1,2,3-benzotriazole (HOBT),O-benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate(HBTU) or O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluroniumtetrafluoroborate (TBTU). In particular, the coupling agent is TBTU.Suitable bases include triethylamine, N-methylmorpholine and,particularly, diisopropylethylamine.

“Under basic conditions” means the presence of a base, in particular abase selected from the group consisting of triethylamine,N-methylmorpholine and, particularly, diisopropylethylamine. Typically,the reaction is carried out in inert solvents such as dimethylformamideor dichloromethane at room temperature.

The invention further relates to compounds of formula I as defined aboveobtainable according to a process as defined above.

The compounds of the present invention can be prepared by anyconventional means. Suitable processes for synthesizing these compoundsas well as their starting materials are provided in the schemes belowand in the examples. All substituents, in particular, R¹ to R⁴ are asdefined above unless otherwise indicated. Furthermore, and unlessexplicitly otherwise stated, all reactions, reaction conditions,abbreviations and symbols have the meanings well known to a person ofordinary skill in organic chemistry.

A general synthetic route for preparing the compounds of formula I isshown in Scheme 1 below. A symbolizes an aryl ring or a heteroaryl ring.

Compounds of formula I can be prepared according to Scheme 1. A couplingreaction between carboxylic acid A and a selected amine IV gives theamide of formula V, which is then protected with an amino protectinggroup such as Boc to obtain a compound of formula VI. Hydrolysis of thecompound of formula VI leads to a carboxylic acid of formula II. Thecarboxylic acid of formula II is then coupled with a selected aryl orheteroarylamine III to obtain an amide of formula VII. Finally, thecompound of formula I is obtained by deprotection of the aminoprotecting group (e.g. Boc) and in situ cyclization of the amide offormula VII. In some cases, the compound of formula VII may contain anadditional acid labile protection group originated from amine IV oramine III, like Boc or TBS, which will be removed also in the finaldeprotection step.

A coupling reagent, like HBTU, is used to couple the carboxylic acid offormula A and a selected amine IV in the presence of a base, like DIPEA,in a solvent like DCM at ambient or elevated temperature to give acompound of formula V.

Then, the compound of formula V is protected with an amino protectinggroup, in particular with Boc, to provide a compound of formula VI.

The compound of formula VI is hydrolyzed by a base, in particular LiOH,in a suitable solvent, for example a mixed solvent like THF/MeOH/H₂O, atambient or elevated temperature to obtain a carboxylic acid of formulaII.

The carboxylic acid of formula II is then reacted with a selectedarylamine or heteroarylamine of formula III under the assistance of asuitable coupling reagent, in particular HATU, in a solvent like DCM andin the presence of a base, in particular DIPEA, at ambient or elevatedtemperature to result in a compound of formula VII.

Finally, a compound of formula I is obtained by treating the compound offormula VII with TFA in dichloromethane (Boc deprotection and in situcyclization) and subsequent purification by prep-HPLC.

If one of the starting materials contains one or more functional groupswhich are not stable or are reactive under the reaction conditions ofone or more reaction steps, appropriate protecting groups (PG) (asdescribed e.g. in T. W. Greene et al., Protective Groups in OrganicChemistry, John Wiley and Sons Inc. New York 1999, 3rd edition) can beintroduced before the critical step applying methods well known in theart. Such protecting groups can be removed at a later stage of thesynthesis using standard methods known in the art. Besides of the Bocprotection group at amidine, a compound of formula VII also contains anadditional acid labile protection group, like Boc or TBS originated fromamine II, which will be also removed in this step.

If one or more compounds of the formula contain chiral centers,compounds of formula I can be obtained as mixtures of diastereomers orenantiomers, which can be separated by methods well known in the art,e.g. (chiral) HPLC or crystallization. Racemic compounds can e.g. beseparated into their antipodes via diastereomeric salts bycrystallization or by separation of the antipodes by specificchromatographic methods using either a chiral adsorbent or a chiraleluent.

As described herein before, the compounds of formula I of the presentinvention can be used as medicaments for the treatment of diseases whichare mediated by TLR agonists, in particular for the treatment ofdiseases which are mediated by TLR8 agonists.

The compounds defined in the present invention are agonists of TLR8receptors in cellular assays in vitro. Accordingly, the compounds of thepresent invention are expected to be potentially useful agents in thetreatment of diseases or medical conditions that may benefit from theactivation of the immune system via TLR8 agonists. They are useful inthe treatment or prevention of diseases such as cancer, autoimmunediseases, inflammation, sepsis, allergy, asthma, graft rejection,graft-versus-host disease, immunodeficiencies, and infectious diseases.

In more detail, the compounds of formula I of the present invention areuseful in oncology, i.e. they may be used in the treatment of commoncancers including bladder cancer, head and neck cancer, prostate cancer,colorectal cancer, kidney cancer, breast cancer, lung cancer, ovariancancer, cervical cancer, liver cancer, pancreatic cancer, bowel andcolon cancer, stomach cancer, thyroid cancer, melanoma, skin and braintumors and malignancies affecting the bone marrow such as leukemias andlymphoproliferative systems, such as Hodgkin's and non-Hodgkin'slymphoma; including the prevention (e.g. vaccination) and treatment ofmetastatic cancer and tumor recurrences, and paraneoplastic syndromes.

The compounds of formula I of the present invention are also useful inthe treatment of autoimmune diseases. An “autoimmune disease” is adisease or disorder arising from and directed against an individual'sown tissues or organs or a co-segregate or manifestation thereof orresulting condition therefrom. “Autoimmune disease” can be anorgan-specific disease (i.e., the immune response is specificallydirected against an organ system such as the endocrine system, thehematopoietic system, the skin, the cardiopulmonary system, thegastrointestinal and liver systems, the renal system, the thyroid, theears, the neuromuscular system, the central nervous system, etc.) or asystemic disease which can affect multiple organ systems (for example,systemic lupus erythematosus (SLE), rheumatoid arthritis, polymyositis,etc.). In a particular aspect, the autoimmune disease is associated withthe skin, muscle tissue, and/or connective tissue.

Particular autoimmune diseases include autoimmune rheumatologicdisorders (such as, for example, rheumatoid arthritis, Sjogren'ssyndrome, scleroderma, lupus such as SLE and lupus nephritis,polymyositis/dermatomyositis, cryoglobulinemia, anti-phospholipidantibody syndrome, and psoriatic arthritis), autoimmune gastrointestinaland liver disorders (such as, for example, inflammatory bowel diseases,ulcerative colitis and Crohn's disease), autoimmune gastritis andpernicious anemia, autoimmune hepatitis, primary biliary cirrhosis,primary sclerosing cholangitis, and celiac disease), vasculitis (suchas, for example, ANCA-negative vasculitis and ANCA-associatedvasculitis, including Churg-Strauss vasculitis, Wegener'sgranulomatosis, and microscopic polyangiitis), autoimmune neurologicaldisorders (such as, for example, multiple sclerosis, opsoclonusmyoclonus syndrome, myasthenia gravis, neuromyelitis optica, Parkinson'sdisease, Alzheimer's disease, and autoimmune polyneuropathies), renaldisorders (such as, for example, glomerulonephritis, Goodpasture'ssyndrome, and Berger's disease), autoimmune dermatologic disorders (suchas, for example, psoriasis, urticaria, hives, pemphigus vulgaris,bullous pemphigoid, and cutaneous lupus erythematosus), hematologicdisorders (such as, for example, thrombocytopenic purpura, thromboticthrombocytopenic purpura, post-transfusion purpura, and autoimmunehemolytic anemia), atherosclerosis, uveitis, autoimmune hearing diseases(such as, for example, inner ear disease and hearing loss), Behcet'sdisease, Raynaud's syndrome, organ transplant, and autoimmune endocrinedisorders (such as, for example, diabetic-related autoimmune diseasessuch as insulin-dependent diabetes mellitus (IDDM), Addison's disease,and autoimmune thyroid disease (e.g., Graves' disease and thyroiditis)),allergic conditions and responses, food allergies, drug allergies,insect allergies, rare allergic disorders such as mastocytosis, allergicreaction, eczema including allergic or atopic eczema, asthma such asbronchial asthma and auto-immune asthma, conditions involvinginfiltration of myeloid cells and T cells and chronic inflammatoryresponses:

The compounds of formula I of the present invention are also useful inthe treatment of infectious diseases. Thus, they may be useful in thetreatment of viral diseases, in particular for diseases caused byinfection with viruses selected from the group consisting of papillomaviruses, such as human papilloma virus (HPV) and those that causegenital warts, common warts and plantar warts, herpes simplex virus(HSV), molluscum contagiosum, hepatitis B virus (HBV), hepatitis C virus(HCV), Dengue virus, variola virus, human immunodeficiency virus (HIV),cytomegalovirus (CMV), varicella zoster virus (VZV), rhinovirus,enterovirus, adenovirus, coronavirus (e.g. SARS), influenza, mumps andparainfluenza.

They may also be useful in the treatment of bacterial diseases, inparticular for diseases caused by infection with bacteria selected fromthe group consisting of mycobacterium such as Mycobacteriumtuberculosis, Mycobacterium avium and Mycobacterium leprae. Thecompounds of formula I of the present invention may further be useful inthe treatment of other infectious diseases, such as chlamydia, fungaldiseases, in particular fungal diseases selected from the groupconsisting of candidiasis, aspergillosis and cryptococcal meningitis,and parasitic diseases such as Pneumocystis camii, pneumonia,cryptosporidiosis, histoplasmosis, toxoplasmosis, trypanosome infectionand leishmaniasis.

Thus, the expression “diseases which are mediated by TLR8 agonists”means diseases which may be treated by activation of the immune systemwith TLR8 agonists such as cancer, autoimmune diseases, inflammation,sepsis, allergy, asthma, graft rejection, graft-versus-host disease,immunodeficiencies, and infectious diseases. In particular, theexpression “diseases which are mediated by TLR agonists” means cancer,autoimmune diseases, inflammation, sepsis, allergy, asthma, graftrejection, graft-versus-host disease, immunodeficiencies, and infectiousdiseases.

In a particular aspect, the expression “which are mediated by TLR8agonists” relates to cancer selected from the group consisting ofbladder cancer, head and neck cancer, liver cancer, prostate cancer,colorectal cancer, kidney cancer, breast cancer, lung cancer, ovariancancer, cervical cancer, pancreatic cancer, bowel and colon cancer,stomach cancer, thyroid cancer, melanoma, skin and brain tumors andmalignancies affecting the bone marrow such as leukemias andlymphoproliferative systems, such as Hodgkin's and non-Hodgkin'slymphoma; including the prevention (e.g. vaccination) and treatment ofmetastatic cancer and tumor recurrences, and paraneoplastic syndromes.

The invention also relates to pharmaceutical compositions comprising acompound of formula I as defined above and a pharmaceutically acceptablecarrier and/or adjuvant. More specifically, the invention relates topharmaceutical compositions useful for the treatment of diseases whichare which are mediated by TLR8 agonists.

Further, the invention relates to compounds of formula I as definedabove for use as therapeutically active substances, particularly astherapeutically active substances for the treatment of diseases whichare which are mediated by TLR8 agonists. In particular, the inventionrelates to compounds of formula I for use in the treatment of cancers orautoimmune diseases or infectious diseases selected from the groupconsisting of viral diseases, bacterial diseases, fungal diseases andparasitic diseases.

In another aspect, the invention relates to a method for the treatment aof diseases which are mediated by TLR8 agonists, which method comprisesadministering a therapeutically active amount of a compound of formula Ito a human being or animal. In particular, the invention relates to amethod for the treatment of cancers and infectious diseases selectedfrom the group consisting of viral diseases, bacterial diseases, fungaldiseases and parasitic diseases.

The invention further relates to the use of compounds of formula I asdefined above for the treatment of diseases which are mediated by TLR8agonists.

In addition, the invention relates to the use of compounds of formula Ias defined above for the preparation of medicaments for the treatment ofdiseases which are mediated by TLR8 agonists. In particular, theinvention relates to the use of compounds of formula I as defined abovefor the preparation of medicaments for the treatment of cancers orautoimmune diseases or infectious diseases selected from the groupconsisting of viral diseases, bacterial diseases, fungal diseases andparasitic diseases.

In a further aspect, compounds of formula I can be in combination withone or more additional treatment modalities in a regimen for thetreatment of cancer.

Combination therapy encompasses, in addition to the administration of acompound of the invention, the adjunctive use of one or more modalitiesthat are effective in the treatment of cancer. Such modalities include,but are not limited to, chemotherapeutic agents, immunotherapeutics,anti-angiogenic agents, cytokines, hormones, antibodies,polynucleotides, radiation and photodynamic therapeutic agents. In aspecific aspect, combination therapy can be used to prevent therecurrence of cancer, inhibit metastasis, or inhibit the growth and/orspread of cancer or metastasis. As used herein, “in combination with”means that the compound of formula I is administered as part of atreatment regimen that comprises one or more additional treatmentmodalities as mentioned above. The invention thus also relates to amethod for the treatment of cancer, which method comprises administeringa therapeutically active amount of a compound of formula I incombination with one or more other pharmaceutically active compounds toa human being or animal.

Compounds of formula I can be used alone or in combination with one ormore additional treatment modalities in treating autoimmune diseases.

Combination therapy encompasses, in addition to the administration of acompound of the invention, the adjunctive use of one or more modalitiesthat aid in the prevention or treatment of autoimmune diseases. Suchmodalities include, but are not limited to, chemotherapeutic agents,immunotherapeutics, anti-angiogenic agents, cytokines, hormones,antibodies, polynucleotides, radiation and photodynamic therapeuticagents. As used herein, “in combination with” means that the compound offormula I is administered as part of a treatment regimen that comprisesone or more additional treatment modalities as mentioned above. Theinvention thus also relates to a method for the treatment of autoimmunediseases, which method comprises administering a therapeutically activeamount of a compound of formula I in combination with one or more otherpharmaceutically active compounds to a human being or animal.

In a further aspect, compounds of formula I can be used alone or incombination with one or more additional treatment modalities in treatinginfectious diseases.

Combination therapy encompasses, in addition to the administration of acompound of the invention, the adjunctive use of one or more modalitiesthat aid in the prevention or treatment of infectious diseases. Suchmodalities include, but are not limited to, antiviral agents,antibiotics, and anti-fungal agents. As used herein, “in combinationwith” means that the compound of formula I is administered as part of atreatment regimen that comprises one or more additional treatmentmodalities as mentioned above. The invention thus also relates to amethod for the treatment of infectious diseases, which method comprisesadministering a therapeutically active amount of a compound of formula Iin combination with one or more other pharmaceutically active compoundsto a human being or animal.

Pharmacological Test

The following tests were carried out in order to determine the activityof the compounds of formula I:

For TLR8 and TLR7 activity testing, HEK-Blue human TLR8 or TLR7 cells(Invivogen, San Diego, Calif., USA) are used, respectively. These cellsare designed for studying the stimulation of human TLR8 or TLR7 bymonitoring the activation of NF-κB. A SEAP (secreted embryonic alkalinephosphatase) reporter gene is placed under the control of the IFN-bminimal promoter fused to five NF-κB and AP-1-binding sites. Thereforethe reporter expression is regulated by the NF-κB promoter uponstimulation of human TLR8 or TLR7 for 20 hours. The cell culturesupernatant SEAP reporter activity was determined using Quanti Blue kit(Invivogen, San Diego, Ca, USA) at a wavelength of 640 nm, a detectionmedium that turns purple/blue in the presence of alkaline phosphatase.EC₅₀ values were determined using Activity Base analysis (ID BusinessSolution, Limited).

VTX-133 and VTX-135 are two examples described in International PatentApplication No. WO 2011/022509 and their activity in HEK-blue human TLR7and TLR8 cells are shown in Table 1.

Of note, the new compounds described in this patent have improvedcellular potency at TLR8 compared to known TLR8 agonists such as VTX-133and VTX-135 described in WO 2011022509. In addition these compounds arehighly specific towards TLR8 with no appreciable activity towards TLR7.Thus, they are expected to possess advantageous properties compared tocombined TLR7/8 agonists due to the more restricted expression patternof TLR8 resulting in less served side effects when administeredsystemically.

The compounds according to formula I have an activity (EC₅₀ value) inthe above assay for human TLR8 in the range of 0.001 μM to 0.03 μM, moreparticularly of 0.001 μM to 0.015 μM, whereas the activity (EC₅₀ value)in the above assay for human TLR7 is greater than 100 μM, meaning thecompounds show very high selectivity towards human TLR8.

For example, the following compounds showed the following EC₅₀ values inthe assay described above:

TABLE 1 human TLR8 EC₅₀ human TLR7 EC₅₀ Example [μM] [μM] VTX-133 0.0771.86 VTX-135 0.039 3.61  1 0.003 >100  2 0.003 >100  3 0.006 >100  40.011 >100  5 0.011 >100  6 0.009 >100  7 0.007 >100  8 0.006 >100  90.001 >100 10 0.003 >100 11 0.002 >100

Pharmaceutical Compositions

The compounds of formula I and their pharmaceutically acceptable saltscan be used as medicaments, e.g., in the form of pharmaceuticalpreparations for enteral, parenteral or topical administration. Thecompounds of formula I and their pharmaceutically acceptable salts maybe administered by systemic (e.g., parenteral) or local (e.g., topicalor intralesional injection) administration. In some instances, thepharmaceutical formulation is topically, parenterally, orally,vaginally, intrauterine, intranasal, or by inhalation administered. Asdescribed herein, certain tissues may be preferred targets for the TLR8agonist. Thus, administration of the TLR8 agonist to lymph nodes,spleen, bone marrow, blood, as well as tissue exposed to virus, arepreferred sites of administration.

In one aspect, the pharmaceutical formulation comprising the compoundsof formula I or its pharmaceutically acceptable salts is administeredparenterally. Parenteral routes of administration include, but are notlimited to, transdermal, transmucosal, nasopharyngeal, pulmonary anddirect injection. Parenteral administration by injection may be by anyparenteral injection route, including, but not limited to, intravenous(IV), including bolus and infusion (e.g., fast or slow), intraperitoneal(IP), intramuscular (IM), subcutaneous (SC) and intradermal (ID) routes.Transdermal and transmucosal administration may be accomplished by, forexample, inclusion of a carrier (e.g., dimethylsulfoxide, DMSO), byapplication of electrical impulses (e.g., iontophoresis) or acombination thereof. A variety of devices are available for transdermaladministration which may be used. Formulations of the compounds offormula I suitable for parenteral administration are generallyformulated in USP water or water for injection and may further comprisepH buffers, salts bulking agents, preservatives, and otherpharmaceutically acceptable excipients.

Transdermal administration is accomplished by application of a cream,rinse, gel, etc. capable of allowing the TLR8 agonist to penetrate theskin and enter the blood stream. Compositions suitable for transdermaladministration include, but are not limited to, pharmaceuticallyacceptable suspensions, oils, creams and ointments applied directly tothe skin or incorporated into a protective carrier such as a transdermaldevice (so-called “patch”). Examples of suitable creams, ointments etc.can be found, for instance, in the Physician's Desk Reference.Transdermal transmission may also be accomplished by iontophoresis, forexample using commercially available patches which deliver their productcontinuously through unbroken skin for periods of several days or more.Use of this method allows for controlled transmission of pharmaceuticalcompositions in relatively great concentrations, permits infusion ofcombination drugs and allows for contemporaneous use of an absorptionpromoter. Administration via the transdermal and transmucosal routes maybe continuous or pulsatile.

Pulmonary administration is accomplished by inhalation, and includesdelivery routes such as intranasal, transbronchial and transalveolarroutes. Formulations of compounds of formula I suitable foradministration by inhalation including, but not limited to, liquidsuspensions for forming aerosols as well as powder forms for dry powderinhalation delivery systems are provided. Devices suitable foradministration by inhalation include, but are not limited to, atomizers,vaporizers, nebulizers, and dry powder inhalation delivery devices.Other methods of delivering to respiratory mucosa include delivery ofliquid formulations, such as by nose drops. Administration by inhalationis preferably accomplished in discrete doses (e.g., via a metered doseinhaler), although delivery similar to an infusion may be accomplishedthrough use of a nebulizer.

The compounds of formula I and pharmaceutically acceptable salts thereofmay also be administered orally, e.g., in the form of tablets, coatedtablets, dragées, hard and soft gelatine capsules.

The production of the pharmaceutical preparations can be effected in amanner which will be familiar to any person skilled in the art bybringing the described compounds of formula I and their pharmaceuticallyacceptable salts, optionally in combination with other therapeuticallyvaluable substances, into a galenical administration form together withsuitable, non-toxic, inert, therapeutically compatible solid or liquidcarrier materials and, if desired, usual pharmaceutical adjuvants.

Suitable carrier materials are not only inorganic carrier materials, butalso organic carrier materials. Thus, for example, lactose, corn starchor derivatives thereof, talc, stearic acid or its salts can be used ascarrier materials for tablets, coated tablets, dragées and hard gelatinecapsules. Suitable carrier materials for soft gelatine capsules are, forexample, vegetable oils, waxes, fats and semi-solid and liquid polyols(depending on the nature of the active ingredient no carriers might,however, be required in the case of soft gelatine capsules). Suitablecarrier materials for the production of solutions and syrups are, forexample, water, polyols, sucrose, invert sugar and the like. Suitablecarrier materials for injection solutions are, for example, water,alcohols, polyols, glycerol and vegetable oils. Suitable carriermaterials for suppositories are, for example, natural or hardened oils,waxes, fats and semi-liquid or liquid polyols. Suitable carriermaterials for topical preparations are glycerides, semi-synthetic andsynthetic glycerides, hydrogenated oils, liquid waxes, liquid paraffins,liquid fatty alcohols, sterols, polyethylene glycols and cellulosederivatives.

Usual stabilizers, preservatives, wetting and emulsifying agents,consistency-improving agents, flavour-improving agents, salts forvarying the osmotic pressure, buffer substances, solubilizers, colorantsand masking agents and antioxidants come into consideration aspharmaceutical adjuvants.

The dosage of the compounds of formula I can vary within wide limitsdepending on the disease to be controlled, the age and the individualcondition of the patient and the mode of administration, and will, ofcourse, be fitted to the individual requirements in each particularcase. For adult patients a daily dosage of about 1 to 1000 mg,especially about 1 to 300 mg, comes into consideration. Depending onseverity of the disease and the precise pharmacokinetic profile thecompound could be administered with one or several daily dosage units,e.g., in 1 to 3 dosage units.

The pharmaceutical preparations conveniently contain about 1-500 mg,preferably 1-100 mg, of a compound of formula I.

The following examples C1 to C3 illustrate typical compositions of thepresent invention, but serve merely as representative thereof.

Example C1

Film coated tablets containing the following ingredients can bemanufactured in a conventional manner:

Ingredients Per tablet Kernel: Compound of formula I  10.0 mg 200.0 mgMicrocrystalline cellulose  23.5 mg  43.5 mg Lactose hydrous  60.0 mg 70.0 mg Povidone K30  12.5 mg  15.0 mg Sodium starch glycolate  12.5 mg 17.0 mg Magnesium stearate  1.5 mg  4.5 mg (Kernel Weight) 120.0 mg350.0 mg Film Coat: Hydroxypropyl methyl cellulose  3.5 mg  7.0 mgPolyethylene glycol 6000  0.8 mg  1.6 mg Talc  1.3 mg  2.6 mg Iron oxide(yellow)  0.8 mg  1.6 mg Titanium dioxide  0.8 mg  1.6 mg

The active ingredient is sieved and mixed with microcrystallinecellulose and the mixture is granulated with a solution ofpolyvinylpyrrolidone in water. The granulate is mixed with sodium starchglycolate and magnesiumstearate and compressed to yield kernels of 120or 350 mg respectively. The kernels are lacquered with an aqueoussolution/suspension of the above mentioned film coat.

Example C2

Capsules containing the following ingredients can be manufactured in aconventional manner:

Ingredients Per capsule Compound of formula I 25.0 mg Lactose 150.0 mgMaize starch 20.0 mg Talc 5.0 mgThe components are sieved and mixed and filled into capsules of size 2.

Example C3

Injection solutions can have the following composition:

Compound of formula I   3.0 mg Polyethylene glycol 400 150.0 mg Aceticacid q.s. ad pH 5.0 Water for injection solutions ad 1.0 ml

The active ingredient is dissolved in a mixture of Polyethylene Glycol400 and water for injection (part). The pH is adjusted to 5.0 by aceticacid. The volume is adjusted to 1.0 ml by addition of the residualamount of water. The solution is filtered, filled into vials using anappropriate overage and sterilized.

The following examples serve to illustrate the present invention in moredetail. They are, however, not intended to limit its scope in anymanner.

Examples

Abbreviations Used Therein:

Boc₂O=di-tert-butyl dicarbonate, Boc=t-butyl carbamate,calc'd=calculated, CD₃OD=deuterated methanol, d=day,DIPEA=N,N-diisopropylethylamine, DCM=dichloromethane, DMAP:4-dimethylaminopyridine, DMF-DMA: N,N-dimethylformamide dimethyl acetal,EA=ethyl acetate or EtOAc, EC₅₀=half maximal effective concentration, hor hr=hour, HBTU=O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluroniumhexafluorophosphate, DMAP=4-dimethylaminopyridine,HATU=(1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium3-oxid hexafluorophosphate), HPLC-UV=high performance liquidchromatography with ultraviolet detector, Hz=hertz, mg=milligram,MHz=megahertz, min=minute(s), mL=milliliter, mm=millimeter, mM=mmol/L,mmol=millimole, MS=mass spectrometry, MW=molecular weight, NMR=nuclearmagnetic resonance, PE=petroleum ether, prep-HPLC=preparative highperformance liquid chromatography, rt=room temperature, sat.=sat.,TBS=tert-butyldimethylsilyl, sxt=sextet, TEA=triethylamine,TFA=trifluoroacetic acid, THF=tetrahydrofuran, μM=micromole/L,μm=micrometer, UV=ultraviolet detector, OD=optical density,TLR8=toll-like receptor 8, TLR7=toll-like receptor 7, NF-κB=nuclearfactor kappa-light-chain-enhancer of activated B cells, SEAP=secretedembryonic alkaline phosphatase, IFN-j3=interferon-beta.

Example A—Preparation of Key Intermediate A2-Amino-8-methoxycarbonyl-3H-1-benzazepine-4-carboxylic Acid

A detailed synthetic route is provided in Scheme 2.

a) Preparation of Compound B

To a solution of methyl 4-methyl-3-nitrobenzoate (100 g, 0.51 mol) inDMF (1 L) was added DMF-DMA (73 g, 0.61 mol). The reaction mixture washeated to 105° C. for 18 hrs. Then the solvent was removed in vacuo togive methyl 4-(2-(dimethylamino)vinyl)-3-nitrobenzoate (compound B, 127g, crude) which was used in the next step without purification. MS:calc'd 251 (M+H)⁺, measured 251(M+H)⁺.

b) Preparation of Compound C

To a solution of NaIO₄ (327 g, 1.53 mol) in a mixed solvent of THF (1.3L) and water (2.0 L) was added a THF (0.7 L) solution of methyl4-(2-(dimethylamino)vinyl)-3-nitrobenzoate (compound A, 127 g, 0.51 mol)at 10° C. After the reaction mixture was stirred at 25° C. for 18 hrs,the mixture was filtered and then extracted with EA. The organic layerwas washed with brine, dried over anhydrous Na₂SO₄, filtered andconcentrated to give the crude product. The crude product was purifiedby silica gel column chromatography (PE:EA=20:1-10:1) to give methyl4-formyl-3-nitrobenzoate (compound C, 84 g, 79%) as a yellow solid. MS:calc'd 210 (M+H)⁺, measured 210 (M+H)⁺.

c) Preparation of Compound D

To a solution of tert-butyl 2-(triphenylphosphoranylidene)acetate (300g, 0.797 mol) in EA (2 L) was added 2-bromoacetonitrile (57 g, 0.479mol) at 25° C. The reaction was heated to reflux for 18 hrs. After itwas cooled to ambient temperature, the solid was filtered and thefiltrate was concentrated. The residue was purified by triturating fromEA and PE (200 mL, 2.5:1) to give the desired product tert-butyl3-cyano-2-(triphenylphosphoranylidene)propanoate (compound D, 125 g,63%) as a white solid. MS: calc'd 416 (M+H)⁺, measured 416 (M+H)⁺.

d) Preparation of Compound E

To a solution of 4-formyl-3-nitrobenzoate (compound C, 50 g, 0.24 mol)in toluene (600 mL) was added tert-butyl3-cyano-2-(triphenylphosphoranylidene)propanoate (compound D, 109 g,0.26 mol) at 25° C. After the reaction mixture was stirred at 25° C. for18 hrs, it was cooled in ice-bath for 1 hr. The precipitate wascollected and dried to give the desired product as a white solid. Thefiltrate was concentrated and treated with EtOH (120 mL). Theundissolved material was filtered and the filtrate was concentrated togive an additional batch of the desired product. These two batches werecombined to give methyl4-(3-(tert-butoxy)-2-(cyanomethyl)-3-oxoprop-1-en-1-yl)-3-nitrobenzoate(compound E, 60 g, 72%). MS: calc'd 347 (M+H)⁺, measured 347 (M+H)⁺.

e) Preparation of Compound F

To a solution of methyl4-(3-(tert-butoxy)-2-(cyanomethyl)-3-oxoprop-1-en-1-yl)-3-nitrobenzoate(compound E, 30 g, 87 mmol) in AcOH (450 mL) was added Fe powder (29.1g, 520 mmol) at 60° C. After the reaction mixture was heated at 85° C.for 3 hrs, it was filtered through celite and the precipitate was washedwith acetic acid. The filtrate was concentrated in vacuo and the residuewas carefully basified with aqueous sat. NaHCO₃ solution (300 mL). ThenEA (600 mL) was added. The mixture was filtered through celite and theprecipitate was washed with EA (200 mL). The filtrate was then washedwith water, dried over Na₂SO₄ and concentrated in vacuo to get4-tert-butyl 8-methyl 2-amino-3H-benzo[b]azepine-4,8-dicarboxylate(compound F, 25 g, 93%) as a light yellow solid. MS: calc'd 317 (M+H)⁺,measured 317 (M+H)⁺.

f) Preparation of Compound A

To a solution of 4-tert-butyl 8-methyl2-amino-3H-benzo[b]azepine-4,8-dicarboxylate (compound F, 25 g, 80 mmol)in dioxane (400 mL) was added a 1 M solution of HCl in dioxane (600 mL)at 0° C. After the reaction mixture was stirred at 25° C. for 18 hrs, itwas concentrated in vacuo to give2-amino-8-(methoxycarbonyl)-3H-benzo[b]azepine-4-carboxylic acidhydrochloride (compound A, 25 g, crude) which was used in the next stepwithout any purification. MS: calc'd 261 (M+H)⁺, measured 261 (M+H)⁺.

Example B—Preparation of Key Intermediate J2-(tert-butoxycarbonylamino)-4-(dipropylcarbamoyl)-3H-1-benzazepine-8-carboxylicAcid

A detailed synthetic route is provided in Scheme 3.

g) Preparation of Compound G

To a mixture of2-amino-8-(methoxycarbonyl)-3H-benzo[b]azepine-4-carboxylic acidhydrochloride (compound A, 19 g, 64 mmol), HBTU (29 g, 77 mmol), DIPEA(33 g, 257 mmol) in DMF (400 mL) was added di-n-propylamine (13 g, 128mmol) at 0° C. After the reaction mixture was stirred at 20° C. for 2hrs, it was quenched with sat. NH₄Cl (500 mL), diluted with H₂O (1 L),and extracted with EA (300 mL×3). The combined organic layers werewashed with brine (300 mL×2), dried over Na₂SO₄ and concentrated to givethe crude product. The crude product was purified by silica gel columnchromatography (PE:EA=1:1) to give methyl2-amino-4-(dipropylcarbamoyl)-3H-benzo[b]azepine-8-carboxylate (compoundG, 18 g, 82%) as a yellow solid. MS: calc'd 344 (M+H)⁺, measured 344(M+H)⁺.

h) Preparation of Compound H

To a mixture of methyl2-amino-4-(dipropylcarbamoyl)-3H-benzo[b]azepine-8-carboxylate (compoundG, 18 g, 53 mmol) and TEA (16 g, 157 mmol) in DCM (300 mL) was addedBoc₂O (17 g, 79 mmol) at 0° C. After the mixture was stirred at 20° C.for 16 hrs, it was quenched with sat. NH₄Cl (300 mL), diluted with H₂O(500 mL), and extracted with DCM (100 mL×3). The combined organic layerswere washed with brine (100 mL×2), dried over Na₂SO₄ and concentrated togive the crude product. The crude product was purified by silica gelcolumn chromatography (PE:EA=3:1) to give methyl2-((tert-butoxycarbonyl)amino)-4-(dipropylcarbamoyl)-3H-benzo[b]azepine-8-carboxylate(compound H, 21 g, yield: 91%) as a yellow solid. MS: calc'd 444 (M+H)⁺,measured 444 (M+H)⁺.

i) Preparation of Compound J

To a solution of methyl2-((tert-butoxycarbonyl)amino)-4-(dipropylcarbamoyl)-3H-benzo[b]azepine-8-carboxylate(compound H, 5.0 g, 11.3 mmol) in THF/H₂O (1/1, 100 mL) was added aq.LiOH solution (1 M, 17 mL, 17 mmol) at 0° C. Then the mixture was warmedto 25° C. and stirred for 6 hrs. The mixture was poured into ice-water(150 mL), acidified with aq. citric acid (5%) to pH=5 and extracted withEtOAc (100 mL×3). The combined organic layers were washed with brine(100 mL×2), dried over Na₂SO₄ and concentrated in vacuo to give2-(tert-butoxycarbonylamino)-4-(dipropylcarbamoyl)-3H-1-benzazepine-8-carboxylicacid (compound J, 4.0 g, 83.3%) as a yellow solid. ¹H NMR (400 MHz,DMSO-d₆) δ ppm=7.78-7.72 (m, 1H), 7.64 (dd, J 1.5, 8.0 Hz, 1H), 7.55 (d,J 8.3 Hz, 1H), 6.93-6.89 (m, 1H), 3.14 (s, 6H), 1.54 (br. s., 4H), 1.44(s, 9H), 0.80 (br. s., 6H). MS: calc'd 430 (M+H)⁺, measured 430 (M+H)⁺.

Example 12-Amino-8-(1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

Example 1 can be prepared according to general procedure in scheme 1. Adetailed synthetic route is provided in Scheme 4.

Preparation of Compound 1B:

To a solution of2-(tert-butoxycarbonylamino)-4-(dipropylcarbamoyl)-3H-1-benzazepine-8-carboxylicacid (compound J, 200 mg, 0.465 mmol) in DMF (4.0 mL) was added HATU(177 mg, 0.550 mmol), DIPEA (84 mg, 0.60 mmol) and tert-butylN-[(2-aminophenyl)methyl]-carbamate (compound 1A, 122 mg, 0.55 mmol).The solution was stirred at 50° C. for 24 hrs. Water (10 mL) was addedand the mixture was extracted with EA (10 mL×2). The organic layer waswashed by brine (10 mL×2), dried over Na₂SO₄ and concentrated in vacuoto give the crude product. The residue was purified by prep-TLC to givetert-butylN-[[2-[[2-(tert-butoxycarbonyl-amino)-4-(dipropylcarbamoyl)-3H-1-benzazepine-8-carbonyl]amino]phenyl]methyl]carbamate (compound 1B, 15 mg) as a yellow solid. MS: calc'd 634 (M+H)⁺,measured 634 (M+H)⁺.

Preparation of Example 1

To a solution of tert-butylN-[[2-[[2-(tert-butoxycarbonylamino)-4-(dipropylcarbamoyl)-3H-1-benzazepine-8-carbonyl]amino]phenyl]methyl]carbamate(compound 1B, 15 mg, 0.023 mmol) in DCM (1.0 ml) was added TFA (0.3 mL).The reaction was stirred at 20° C. for 2 hrs. Then the reaction mixturewas concentrated and the residue was purified by preparative HPLC togive2-amino-8-(1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide(Example 1, 12 mg) as a yellow solid. ¹H NMR (400 MHz, MeOD) δppm=7.89-7.85 (m, 3H), 7.42-7.36 (m, 2H), 7.29-7.25 (m, 2H), 7.16 (s,1H), 5.01 (s, 2H), 3.48 (m, 4H), 3.41 (s, 2H), 1.74-1.69 (m, 4H),1.00-0.93 (m, 6H). MS: calc'd 416 (M+H)+, measured 416 (M+H)+.

Example 22-Amino-8-(1,4-dihydropyrido[3,4-d]pyrimidin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 1 by usingtert-butyl ((3-aminopyridin-4-yl)methyl)carbamate instead of tert-butyl2-aminobenzylcarbamate. Example 2 was obtained (16 mg) as a yellowsolid. ¹H NMR (400 MHz, MeOD) δ ppm=8.44 (m, 2H), 7.84-7.80 (m, 3H),7.33-7.27 (m, 1H), 7.01 (s, 1H), 4.94 (s, 2H), 3.41-3.16 (m, 6H),1.75-1.55 (m, 4H), 1.15-0.8 (m, 6H). MS: calc'd 417 (M+H)+, measured 417(M+H)+.

Example 32-Amino-N-(cyclopropylmethyl)-8-(1,4-dihydroquinazolin-2-yl)-N-propyl-3H-1-benzazepine-4-carboxamide

A detailed synthetic route is provided in Scheme 5.

The title compound was prepared in analogy to Example 1 by using2-((tert-butoxycarbonyl)amino)-4-((cyclopropylmethyl)(propyl)carbamoyl)-3H-benzo[b]azepine-8-carboxylicacid (compound 3A) instead of2-(tert-butoxycarbonylamino)-4-(dipropylcarbamoyl)-3H-1-benzazepine-8-carboxylicacid (compound J). Example 3 was obtained (2 mg) as a white solid. ¹HNMR (400 MHz, MeOD) δ ppm=7.87-7.85 (m, 3H), 7.42-7.36 (m, 2H),7.30-7.24 (m, 2H), 7.17 (s, 1H), 5.04 (s, 2H), 3.61-3.59 (m, 2H),3.44-3.41 (m, 4H), 1.76-1.74 (m, 2H), 1.31 (br s, 1H), 1.11-0.97 (br s,3H), 0.64 (br s, 2H), 0.31 (br s, 2H). MS: calc'd 428 (M+H)⁺, measured428 (M+H)⁺.

Preparation of Compound 3A:

The title compound was prepared in analogy to key intermediate J ofExample B by using N-(cyclopropylmethyl)propan-1-amine instead ofdi-n-propylamine.

Example 42-Amino-8-(1,4-dihydroquinazolin-2-yl)-N-isobutyl-N-propyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 3 by using2-methyl-N-propylpropan-1-amine instead ofN-(cyclopropylmethyl)propan-1-amine. Example 4 was obtained (4.5 mg) asa yellow solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.87-7.83 (m, 3H),7.35-7.27 (m, 4H), 7.14 (s, 1H), 5.03 (s, 2H), 3.38 (br s, 6H), 1.75-1.6(m, 3H), 0.92 (br s, 9H). MS: calc'd 430 (M+H)+, measured 430 (M+H)⁺.

Example 52-Amino-8-(5-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 1 by usingtert-butyl 2-amino-6-chlorobenzylcarbamate (compound 5C) instead oftert-butyl N-[(2-aminophenyl)methyl]-carbamate. Example 5 was obtained(19 mg) as a white solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.76-7.72 (m,3H), 7.79-7.78 (m, 2H), 7.03 (s, 2H), 4.92 (s, 2H), 3.37 (br s, 6H),1.61-1.59 (m, 4H), 1.00-0.93 (m, 6H). MS: calc'd 450 (M+H)⁺, measured450 (M+H)⁺.

The preparation of compound 5C is shown in scheme 6.

To a solution of 2-chloro-6-nitrobenzonitrile (compound 5A, 2.0 g, 10.98mmol) in THF (20 mL) was added BH₃.THF (33 mL, 32.9 mmol). The solutionwas refluxed for 3 hrs. The reaction solution was cooled under ice-bathand then MeOH (20 mL) was added dropwise. The solution was stirred for30 min and then Boc₂O (2.63 g, 12.1 mmol) was added. The solution wasstirred at 20° C. for 3 hrs. After the reaction solution wasconcentrated in vacuo, the residue was purified by column chromatography(PE/EtOAc=20/1-5/1) to give crude tert-butyl2-chloro-6-nitrobenzylcarbamate (compound 5B, 1.4 g, 44.5%) as yellowoil, which was used for the next step directly. MS: calc'd 287 (M+H)⁺,measured 287 (M+H)⁺.

To a solution of tert-butyl 2-chloro-6-nitrobenzylcarbamate (compound5B, 1.4 g, 4.9 mmol) in MeOH (70 mL) was added NH₄Cl (3.6 g, 68.5 mmol)and Zn (2.79 g, 44.0 mmol). The solution was stirred at 20° C. for 2hrs. The reaction solution was concentrated in vacuo. Water (30 mL) wasadded, and the mixture was extracted with EA (30 mL). The organic layerwas washed with brine, dried over anhydrous Na₂SO₄ and concentrated invacuo to give tert-butyl 2-amino-6-chlorobenzylcarbamate (compound 5C,800 mg, 64%) as a yellow solid, which was used for the next stepdirectly. MS: calc'd 257 (M+H)⁺, measured 257 (M+H)⁺.

Example 62-Amino-8-(7-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 5 by usingtert-butyl 2-amino-4-chlorobenzylcarbamate instead of tert-butylN-[(2-aminophenyl)methyl]carbamate. Example 5 was obtained (5 mg) as awhite solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.88-7.84 (m, 3H), 7.35-7.28(m, 3H), 7.15 (s, 1H), 5.01 (s, 2H), 3.48-3.40 (m, 6H), 1.75-1.68 (m,4H), 0.96 (br s, 6H). MS: calc'd 450 (M+H)+, measured 450 (M+H)+.

Example 72-Amino-8-(4,4-dimethyl-1H-quinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 1 by using2-(2-aminopropan-2-yl)aniline instead of tert-butylN-[(2-aminophenyl)methyl]carbamate. Example 7 was obtained (18 mg) as awhite solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.86 (brs, 3H), 7.51-7.25 (m,4H), 7.17 (s, 1H), 3.55-3.40 (m, 6H), 1.86 (s, 6H), 1.73-1.71 (m, 4H),0.97 (br s, 6H). MS: calc'd 444 (M+H)⁺, measured 444 (M+H)⁺.

Example 82-Amino-8-(6-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 5 by usingtert-butyl 2-amino-5-chlorobenzylcarbamate instead of tert-butyl2-amino-6-chlorobenzylcarbamate. Example 8 was obtained (6 mg) as awhite solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.86-7.83 (m, 3H), 7.42-7.23(m, 3H), 7.15 (s, 1H), 5.02 (s, 2H), 3.49-3.39 (m, 6H), 1.74-1.69 (m,4H), 1.00-0.92 (br s, 6H). MS: calc'd 450 (M+H)⁺, measured 450 (M+H)⁺.

Example 92-Amino-8-(5-methyl-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 5 by usingtert-butyl 2-amino-6-methylbenzylcarbamate instead of tert-butyl2-amino-6-chlorobenzylcarbamate. Example 9 was obtained (29 mg) as awhite solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.87-7.85 (m, 3H), 7.30-7.28(m, 1H), 7.20-7.16 (m, 2H), 7.06-7.04 (s, 1H), 4.99 (s, 2H), 3.48 (br s,4H), 3.41 (s, 2H), 2.30 (s, 3H), 1.75-1.69 (m, 4H), 0.99-0.93 (br s,6H). MS: calc'd 430 (M+H)⁺, measured 430 (M+H)⁺.

Example 102-Amino-8-(5-fluoro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 5 by usingtert-butyl 2-amino-6-fluorobenzylcarbamate instead of tert-butyl2-amino-6-chlorobenzylcarbamate. Example 10 was obtained (5 mg) as awhite solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.87-7.83 (m, 3H), 7.46-7.40(m, 1H), 7.13-7.06 (m, 3H), 5.03 (s, 2H), 3.46-3.31 (br s, 4H), 3.30 (s,2H), 1.72-1.67 (m, 4H), 0.98-0.97 (br s, 6H). MS: calc'd 434 (M+H)⁺,measured 434 (M+H)⁺.

Example 112-Amino-8-(6-methoxy-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide

The title compound was prepared in analogy to Example 5 by usingtert-butyl 2-amino-5-methoxybenzylcarbamate instead of tert-butyl2-amino-6-chlorobenzylcarbamate. Example 11 was obtained (37 mg) as awhite solid. ¹H NMR (400 MHz, MeOD) δ ppm=7.85-7.84 (m, 3H), 7.21-7.15(m, 2H), 6.99-6.96 (m, 1H), 6.87-6.86 (m, 1H), 5.00 (s, 2H), 3.85 (s,3H), 3.48 (br s, 4H), 3.41 (s, 2H), 2.30 (s, 3H), 1.74-1.69 (m, 4H),1.00-0.93 (br s, 6H). MS: calc'd 446 (M+H)⁺, measured 446 (M+H)⁺.

The invention claimed is:
 1. A method for the treatment of sepsis,allergy, asthma, graft rejection, graft-versus-host disease, orimmunodeficiencies, the method comprising administering to a subject atherapeutically effective amount of a compound of formula I

wherein R¹ is C₃₋₇-alkyl; R² is C₃₋₇-alkyl orC₃₋₇-cycloalkyl-C₁₋₇-alkyl; R³ is hydrogen or C₁₋₇-alkyl; R⁴ is hydrogenor C₁₋₇-alkyl; R⁵ is selected from the group consisting of hydrogen,halogen, C₁₋₇-alkyl and C₁₋₇-alkoxy; R⁶ is selected from the groupconsisting of hydrogen, halogen, C₁₋₇-alkyl and C₁₋₇-alkoxy; X is N orCR⁷, wherein R⁷ is selected from the group consisting of hydrogen,halogen, C₁₋₇-alkyl and C₁₋₇-alkoxy; or a pharmaceutically acceptablesalt thereof.
 2. The method of claim 1 wherein in the compound offormula I, or a pharmaceutically acceptable salt thereof, R¹ isn-propyl.
 3. The method of claim 1 wherein in the compound of formula I,or a pharmaceutically acceptable salt thereof, R² is selected from thegroup consisting of n-propyl, isobutyl and cyclopropylmethyl.
 4. Themethod of claim 1 wherein in the compound of formula I, or apharmaceutically acceptable salt thereof, R¹ and R² are n-propyl.
 5. Themethod of claim 1 wherein in the compound of formula I, or apharmaceutically acceptable salt thereof, R³ and R⁴ are hydrogen.
 6. Themethod of claim 1 wherein in the compound of formula I, or apharmaceutically acceptable salt thereof, R³ and R⁴ are methyl.
 7. Themethod of claim 1 wherein in the compound of formula I, or apharmaceutically acceptable salt thereof, X is CR⁷ and R⁷ is selectedfrom the group consisting of hydrogen, halogen, C₁₋₇-alkyl andC₁₋₇-alkoxy.
 8. The method of claim 1 wherein in the compound of formulaI, or a pharmaceutically acceptable salt thereof, R⁷ is hydrogen orhalogen.
 9. The method of claim 1 wherein in the compound of formula I,or a pharmaceutically acceptable salt thereof, X is N.
 10. The method ofclaim 1 wherein in the compound of formula I, or a pharmaceuticallyacceptable salt thereof, R⁵ is selected from the group consisting ofhydrogen, halogen and C₁₋₇-alkyl.
 11. The method of claim 1 wherein inthe compound of formula I, or a pharmaceutically acceptable saltthereof, R⁶ is selected from the group consisting of hydrogen, halogenand C₁₋₇-alkoxy.
 12. The method of claim 1 wherein in the compound offormula I, or a pharmaceutically acceptable salt thereof is selectedfrom:2-amino-8-(1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(1,4-dihydropyrido[3,4-d]pyrimidin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-N-(cyclopropylmethyl)-8-(1,4-dihydroquinazolin-2-yl)-N-propyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(1,4-dihydroquinazolin-2-yl)-N-isobutyl-N-propyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(5-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(7-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(4,4-dimethyl-1H-quinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(6-chloro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(5-methyl-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;2-amino-8-(5-fluoro-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide;or2-amino-8-(6-methoxy-1,4-dihydroquinazolin-2-yl)-N,N-dipropyl-3H-1-benzazepine-4-carboxamide,or a pharmaceutically acceptable salt thereof.
 13. The method of claim 1wherein the treatment is for sepsis.
 14. The method of claim 1 whereinthe treatment is for allergy.
 15. The method of claim 1 wherein thetreatment is for asthma.
 16. The method of claim 1 wherein the treatmentis for graft rejection.
 17. The method of claim 1 wherein the treatmentis for graft-versus-host disease.
 18. The method of claim 1 wherein thetreatment is for immunodeficiencies.